Extra ajax request on Debian os

Hey everybody
I installed my application in two different os machines (Centos and Debian), everything is ok in centos but in debian one ajax request sent which I dont have any idea about it. I used live search grid panel inside my appalication and the unwanted request is received from that js.
sth like this in console:

As I implemented ACL for each action in my php code, the response of above request is '
You are not authorized for this action.' Now I dont know what is this and who or where it call, but it make a problem for me. please help